NTA Abhyas JEE Main2020PhysicsRay OpticsPractice
Image of an object approaching a convex mirror of radius of curvature 20 m along its optical axis is observed to move from 25 3 m to 50 7 m in 30 s . If the object is moving uniformly, then its speed is
Options
- A3 k m h - 1
- B4 k m h - 1
- C5 k m h - 1
- D6 k m h - 1
Correct answer
A. 3 k m h - 1
Step-by-step solution
Using mirror formula, Or 1 u 1 = 3 25 - 1 10 Or u 1 = 50 m And ∴ 1 u 2 = 7 50 - 1 10 Or u 2 = 25 m Speed of object = u 1 - u 2 t i m e = 25 30 m s - 1 = 3 k m h - 1